Detection of Homologous Recombination Pathway Gene Mutations in Circulating Tumour DNA From BRCA-mutated Ovarian Cancer Patients Receiving First-line PARP Inhibitor Maintenance Therapy

Inclusion Criteria: 1. Patient with an epithelial ovarian cancer, fallopian tube cancer or primitive of the peritoneum. 2. Patient with a BRCA 1 or 2 somatic and/or constitutional mutation previously confirmed and validated by an approved laboratory. 3. Patient due to start first-line maintenance treatment with Olaparib alone (PARP inhibitor) or in combination with bevacizumab. 4. Age ≥ 18 years at the time of signing the consent. 5. WHO ≤ 1. 6. Patient affiliated to a Social Security scheme in France. 7. Patient having signed informed consent prior to inclusion in the study and prior to any specific procedure for the study. Exclusion Criteria: 1. Other cancer under treatment. 2. Olaparib treatment already initiated. 3. Indication for treatment with a PARP inhibitor other than Olaparib. 4. Any pathology contraindicating the sample collection procedures required by the study. 5. Any psychological, family, geographical or sociological condition that makes it impossible to comply with medical monitoring and/or the procedures laid down in the study protocol. 6. Subjects deprived of their liberty or under legal protection.